Project GT3 RS Part 4: Dynos and Doughnuts

With the new, Autometrics-Motorsports-built 4.0 liter engine and transmission in place, it was time for the GT3 RS to head off to the dyno to measure the new and improved power figures.

So how does Leh Keen’s RS measure up? Quite well, actually.

In the dyno chart below the Autometrics 4.0 liter conversion (blue line) is overlaid with the exclusive (only 600 built globally) factory Porsche GT3 RS 4.0 (red line). The first thing that stands out is the power curve of the Autometrics Motorsports engine. From the moment full throttle is applied at around 3,500rpm the 4.0 liter conversion makes more power than the factory 4.0 at nearly every point save the final few hundred revs. Ditto for torque. The result is a powerplant that pulls strongly and smoothly to a total of 459 rear wheel horsepower. That, and Autometrics Motorsports getting profane text messages from a happy Leh Keen.

Some tuners proudly display peak horsepower numbers. And while we could produce even larger numbers with ultra-high compression pistons, individual throttles and astronomical rpm, this isn’t the sort of thing we’d ever want to drive on the road. Real world cars need to idle smoothly, build revs easily across the rev range, and be able to fuel up someplace other than the airport. Leh Keen’s newly built 4.0 liter does all of this and more. And by “more” we mean spitting blue flames from the exhaust and spinning the rear wheels at highway speeds.

But don’t take our word it. Read Leh Keen’s summary of the project here on Rennlist Porsche Forum and watch the above video. And if you’d like to have a 4.0 liter built to your specifications, contact Autometrics Motorsports.